The present invention relates to enclosure feeders in an envelope inserting machine for mass mailing.
In an envelope inserting machine for mass mailing, there is a gathering section where the enclosure material is gathered before it is inserted into an envelope. This gathering section is sometimes referred to as a chassis subsystem, which includes a gathering transport with pusher fingers rigidly attached to a conveying mechanism and a plurality of enclosure feeders mounted above the gathering transport for releasing the enclosure material onto the gathering transport. If the enclosure material contains many documents, these documents must be separately fed from different enclosure feeders. Envelope inserting systems and enclosure feeders have been disclosed in the past. For example, U.S. Pat. No. 4,169,341 (Roetter et al) discloses an envelope inserting system having a plurality of enclosure feeders and a gathering transport. As shown in FIG. 1, such an envelope inserting system has a number of feeding stations or enclosure feeders over a longitudinally extending deck. Each enclosure feeder has a hopper capable of holding documents therein, and a plurality of rollers to release the documents, one at a time, to a ledge plate. Also shown in FIG. 1 are a plurality of pusher fingers fixedly mounted on a pair of endless chains which run along the deck for pushing the released documents off the ledge plates onto the deck. As shown in FIG. 2, the pusher fingers are arranged in pairs and the distance between two adjacent pairs of pusher fingers is substantially equal to the distance between two adjacent enclosure feeders. Moreover, the endless chains are substantially parallel to each other from the upstream end to the envelope insertion area. The endless chains move in synchronism and in constant speed. The pusher fingers are also used to push the released enclosure documents toward the envelope insertion area. As these pusher fingers move from the upstream end of the envelope inserting system toward the downstream end, each pair of pusher fingers gathers one released document from each releasing enclosure feeder and the gathered documents are stacked and collated while they are pushed toward the envelope insertion area for insertion.
It should be noted that the ledge plates as shown in FIG. 1 and FIG. 2 are rigid in construction. The downstream end of each ledge plate has a fixed gap from the deck so as to allow the documents gathered from the upstream enclosure feeders to move through the gap of the downstream enclosure feeders. As such, the document released from a downstream enclosure feeder is stacked on top of the documents released from the upstream enclosure feeders. While it is not desirable to have a large gap between the ledge plate and the deck because a large gap tends to make collating of the gathered documents more difficult, a small gap limits the number of documents that can be gathered by the pusher fingers. Furthermore, the width of the ledge plates must be made to match the size of the released documents and the separation between the endless chains. Moreover, the ledge plate requires a precision positioning of the document released onto it. If the document is released too far downstream, the document would tip off the downstream end of the ledge plate, elevating the trailing edge of the released document. A jam caused by the pusher finger would result.
It is advantageous and desirable to provide a method and device for releasing and gathering documents in an envelope inserting machine to overcome the aforementioned disadvantages associated with the ledge plates.
The first aspect of the present invention is to provide an enclosure feeder wherein a plurality of ledge-extension fingers are used to support a sheet of enclosure material released from an enclosure feeder. The ledge-extension fingers are flexible so that the gap between the downstream end of the ledge-extension fingers and the transport deck can be made small so as to help the stacking and collating of the release documents. At the same time, the number of the documents to be inserted into an envelope can be increased because the ledge-extension fingers can be pushed upward by the gathered documents to widen the gap when the gathered documents move through the gap.
The second aspect of the present invention is to provide an envelope inserting system having an envelope feeder, a plurality of enclosure feeders, and a gathering mechanism moving from the downstream end of the envelope inserting system toward an envelope insertion area at the upstream end, wherein each enclosure feeder has a plurality of ledge-extension fingers and can be used to release enclosure documents one at a time onto the ledge-extension fingers so as to allow the gather mechanism to collect the release documents in an orderly fashion and move the release documents downstream. The envelope inserting system further includes at least one centering device for centering the released documents while the released documents are moved by the gather mechanism downstream.
The third aspect of the present invention is to provide a method of gathering enclosure documents for insertion into an envelope inserting system having a plurality of enclosure feeders to release the enclosure documents. The method comprises the steps of providing a plurality of enclosure documents on at least one enclosure feeder, releasing documents from said at least one enclosure feeder one at a time onto a plurality of flexible ledge-extension fingers, pushing the released documents off the ledge-extension fingers in order to move the released documents downstream, and centering the released documents while they are pushed downstream.
The object and the scope of the present invention will become apparent upon reading the description taken in conjunction with FIG. 3 to FIG. 6.